WO2002041506A2 - Apparatus for receiving and recovering frequency shift keyed symbols - Google Patents
Apparatus for receiving and recovering frequency shift keyed symbols Download PDFInfo
- Publication number
- WO2002041506A2 WO2002041506A2 PCT/US2001/043413 US0143413W WO0241506A2 WO 2002041506 A2 WO2002041506 A2 WO 2002041506A2 US 0143413 W US0143413 W US 0143413W WO 0241506 A2 WO0241506 A2 WO 0241506A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- filter
- transmitter
- symbols
- discriminator
- selectivity
- Prior art date
Links
- 238000011084 recovery Methods 0.000 claims abstract description 29
- 238000007476 Maximum Likelihood Methods 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims abstract description 8
- 238000004891 communication Methods 0.000 claims description 21
- 238000001514 detection method Methods 0.000 claims description 9
- 230000005540 biological transmission Effects 0.000 claims description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000035945 sensitivity Effects 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/14—Demodulator circuits; Receiver circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03178—Arrangements involving sequence estimation techniques
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03343—Arrangements at the transmitter end
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/22—Demodulator circuits; Receiver circuits
- H04L27/233—Demodulator circuits; Receiver circuits using non-coherent demodulation
- H04L27/2334—Demodulator circuits; Receiver circuits using non-coherent demodulation using filters
Definitions
- This invention relates in general to wireless communication systems, and more specifically to an apparatus for receiving and recovering frequency shift keyed symbols.
- Digital wireless communication systems have utilized many different types of modulation for transmitting data.
- One type of modulation which has become popular is Gaussian frequency shift keyed (GFSK) modulation.
- GFSK Gaussian frequency shift keyed
- the well-known Bluetooth wireless communication system for example, utilizes two-level GFSK modulation.
- a GFSK modulator performs filtering on the data symbols to be transmitted in order to limit the transmission bandwidth.
- This transmitter filter causes a significant amount of inter-symbol interference (ISI), making the symbols harder to detect in a receiver.
- ISI inter-symbol interference
- prior-art GFSK receivers have generally utilized relatively wide-band selectivity filters, thereby reducing adjacent channel rejection.
- Additional elements such as a post-detection filter (PDF) and a maximum likelihood sequence estimation (MLSE) element having four or sixteen states for a two-level GFSK channel, have been used to compensate for the ISI.
- PDF post-detection filter
- MLSE maximum likelihood sequence estimation
- the templates of the MLSE are generally used with a bandwidth matching that of the transmitter filter. Such additional elements add to the cost of the receiver and increase the total power consumption.
- the apparatus preferably will achieve high sensitivity and adjacent channel rejection without requiring either the PDF or the four- or sixteen-state MLSE element.
- FIG. 1 is an electrical block diagram of a prior-art transceiver.
- FIG. 2 is an electrical block diagram of a receiver in accordance with the present invention.
- FIG. 3 is an electrical block diagram of a transceiver in accordance with the present invention.
- FIG. 4 is an electrical block diagram of a wireless communication system including a wireless headset in accordance with the present invention.
- an electrical block diagram of a prior-art transceiver 100 comprises a transmitter 101 and a receiver 103.
- the transmitter 101 preferably includes a Gaussian -transmitter filter 102 having the ratio of the half -bandwidth B to the symbol rate 1/T (BT) of 0.5.
- the transmitter filter 102 is coupled to an FM modulator 104 for generating a GFSK radio signal.
- An antenna 106 is coupled to the FM modulator for transmitting the signal.
- the receiver 103 includes an antenna 108 for intercepting the GFSK signal from the transmitter 101.
- the antenna 108 is coupled to a down-converter 110 for down-converting the received signal.
- the down-converter 110 is coupled to a selectivity filter 112 for selectively tuning a desired channel, rejecting the adjacent channel interference, and reducing the AWGN bandwidth. It has been generally accepted that the bandwidth of the selectivity filter should be not less than the bandwidth of the transmitted GFSK signal, so that the inter-symbol interference (ISI) does not become severe.
- ISI inter-symbol interference
- a discriminator 114 is coupled to the selectivity filter 112 for converting the frequency-domain symbols of the received signal to time-domain symbols.
- a post detection filter (PDF) 116 is coupled to the discriminator 114 for reducing the noise non-linearly amplified by the discriminator.
- a slicing element 118 is coupled to the PDF for symbol recovery.
- FIG. 2 an electrical block diagram of a receiver 200 in accordance with the present invention comprises a conventional antenna 202 for intercepting the GFSK signal from the transmitter 101.
- the antenna 202 is coupled to a conventional down-converter 204 for down-converting the received signal.
- the down-converter 204 is preferably coupled to a fourth-order selectivity filter 206 for selectively tuning the desired channel.
- a conventional discriminator 208 is coupled to the selectivity filter 206 for converting the frequency-domain symbols of the received signal to time-domain symbols.
- a symbol recovery processor 210 is coupled to the discriminator 208 for recovering the symbols preferably through a two-state maximum likelihood sequence estimation (MLSE) technique.
- MLSE maximum likelihood sequence estimation
- the templates used in the MLSE are optimized with a bandwidth substantially less than the transmitter filter bandwidth. More specifically, to compensate for the ISI caused by both the Gaussian filter 102 of the transmitter 101 and the selectivity filter 206, the templates preferably are optimized with a BT equal to the transmitter filter BT divided by approximately the square root of three. Note that no post detection filter is required in this receiver architecture, because the unusually narrow bandwidth of the selectivity filter alone provides ample adjacent channel rejection and AWGN noise bandwidth reduction. It will be appreciated that, alternatively, the selectivity filter bandwidth and the templates can be adjusted somewhat about the preferred values, depending upon design preference. It will be further appreciated that all or a portion of the receiver 200 can be manufactured in the form of one or more integrated circuits.
- the receiver 200 is designed to operate in a Bluetooth communication system.
- This embodiment requires the selectivity filter 206, the discriminator 208, and the symbol recovery processor 210 to be arranged and programmed to receive and recover symbols transmitted in a two-level Gaussian frequency shift keyed (2-GFSK) channel having a data rate of 1 Mbps and a transmitter filter BT of 0.5.
- 2-GFSK two-level Gaussian frequency shift keyed
- the receiver 200 can be operated in other systems at other data rates with other forms of modulation and other transmission bandwidths.
- FIG. 3 is an electrical block diagram of a transceiver 300 in accordance with the present invention.
- the transceiver 300 comprises the receiver 200 and the transmitter 101, both coupled to a communications processor 302 for controlling the receiver 200 and the transmitter 101.
- the transceiver 300 is operated in a Bluetooth communication system.
- FIG. 4 is an electrical block diagram of a wireless communication system 400 including a wireless headset 401 in accordance with the present invention.
- the wireless communication system 400 includes a cellphone 406 equipped with a wireless headset interface (not shown), preferably similar to the transceiver 300.
- the wireless headset 401 includes the transmitter 101 and the receiver 200 coupled to the communications processor 302 for communicating with the cellphone 406 over a first wireless link 410. Also coupled to the communications processor 302 are a first transducer or microphone 402 for receiving a speech input from a user, and a second transducer or ear speaker 404 for conveying to the user a message received over the first wireless link 410.
- the cellphone 406 also communicates conventionally with the cellular infrastructure 408 over a second wireless link 412.
- the wireless communication system 400 advantageously allows the user to operate the cellphone 406 in a headset mode without requiring a cord between the cellphone 406 and the wireless headset 401.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2002239293A AU2002239293A1 (en) | 2000-11-10 | 2001-11-06 | Apparatus for receiving and recovering frequency shift keyed symbols |
GB0309875A GB2386305B (en) | 2000-11-10 | 2001-11-06 | Apparatus for receiving and recovering frequency shift keyed symbols |
KR1020037006005A KR100544245B1 (en) | 2000-11-10 | 2001-11-06 | Apparatus for receiving and recovering frequency shift keyed symbols |
JP2002543796A JP3968304B2 (en) | 2000-11-10 | 2001-11-06 | Apparatus for receiving and recovering frequency shift keyed symbols |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/709,687 US6487240B1 (en) | 2000-11-10 | 2000-11-10 | Apparatus for receiving and recovering frequency shift keyed symbols |
US09/709,687 | 2000-11-10 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2002041506A2 true WO2002041506A2 (en) | 2002-05-23 |
WO2002041506A3 WO2002041506A3 (en) | 2002-09-06 |
Family
ID=24850927
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2001/043413 WO2002041506A2 (en) | 2000-11-10 | 2001-11-06 | Apparatus for receiving and recovering frequency shift keyed symbols |
Country Status (7)
Country | Link |
---|---|
US (3) | US6487240B1 (en) |
JP (1) | JP3968304B2 (en) |
KR (1) | KR100544245B1 (en) |
CN (1) | CN100358325C (en) |
AU (1) | AU2002239293A1 (en) |
GB (1) | GB2386305B (en) |
WO (1) | WO2002041506A2 (en) |
Families Citing this family (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6487240B1 (en) | 2000-11-10 | 2002-11-26 | Motorola, Inc. | Apparatus for receiving and recovering frequency shift keyed symbols |
GB2377129B (en) * | 2001-06-29 | 2005-05-11 | Nokia Corp | Wireless communication device and method |
CA2474897C (en) * | 2002-02-12 | 2012-03-13 | Michael Robert Fitch | Gaussian fsk modulation with more than two modulation states |
US7317714B2 (en) * | 2002-06-21 | 2008-01-08 | At&T Deleware Intellectual Property, Inc. | Internet call waiting messaging |
US6931117B2 (en) * | 2002-06-21 | 2005-08-16 | Bellsouth Intellectual Property Corporation | Caller control of internet call waiting |
US7027842B2 (en) * | 2002-09-24 | 2006-04-11 | Bellsouth Intellectual Property Corporation | Apparatus and method for providing hands-free operation of a device |
US7899500B2 (en) * | 2002-09-24 | 2011-03-01 | At&T Intellectual Property I, L. P. | Apparatus and method for providing hands-free operation of a device |
US8849185B2 (en) * | 2003-04-15 | 2014-09-30 | Ipventure, Inc. | Hybrid audio delivery system and method therefor |
US7818037B2 (en) * | 2003-09-19 | 2010-10-19 | Radeum, Inc. | Techniques for wirelessly controlling push-to-talk operation of half-duplex wireless device |
US7149552B2 (en) * | 2003-09-19 | 2006-12-12 | Radeum, Inc. | Wireless headset for communications device |
US7818036B2 (en) * | 2003-09-19 | 2010-10-19 | Radeum, Inc. | Techniques for wirelessly controlling push-to-talk operation of half-duplex wireless device |
CN101064707B (en) * | 2006-04-28 | 2010-05-12 | 北京泰美世纪科技有限公司 | Bandlimited stochastic sequence generating method and its apparatus |
US8731146B2 (en) | 2007-01-04 | 2014-05-20 | At&T Intellectual Property I, L.P. | Call re-directed based on voice command |
US8625722B2 (en) * | 2010-07-30 | 2014-01-07 | Sensus Usa Inc. | GFSK receiver architecture and methodology |
WO2012131735A1 (en) * | 2011-03-31 | 2012-10-04 | Aeb Industriale S.R.L. | Digital microphone radio transmission system |
US9306781B2 (en) * | 2014-04-01 | 2016-04-05 | Samsung Electronics Co., Ltd | Apparatus and method for receiving signal in communication system supporting Gaussian frequency shift keying modulation scheme |
KR101817544B1 (en) * | 2015-12-30 | 2018-01-11 | 어보브반도체 주식회사 | Bluetooth signal receiving method and device using improved carrier frequency offset compensation |
KR101828790B1 (en) | 2015-12-30 | 2018-03-29 | 어보브반도체 주식회사 | Frequency shift keying signal receiving method and device |
KR101824399B1 (en) * | 2015-12-30 | 2018-02-01 | 어보브반도체 주식회사 | Bluetooth signal receiving method and device using improved packet detection and symbol timing acquisition |
KR101906149B1 (en) | 2015-12-30 | 2018-10-10 | 어보브반도체 주식회사 | Bluetooth signal receiving method and device using improved symbol timing offset compensation |
KR101790960B1 (en) | 2015-12-30 | 2017-11-20 | 어보브반도체 주식회사 | Bluetooth smart signal receiving method and device using improved automatic gain control |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5208835A (en) * | 1990-09-24 | 1993-05-04 | In-Situ, Inc. | Automatic frequency control system and method for frequency-shift-key data transmission systems |
US5852636A (en) * | 1997-08-08 | 1998-12-22 | Serge Mathieu | Method of and apparatus for modulation of FSK carrier in a very narrow band |
US6266521B1 (en) * | 1997-09-02 | 2001-07-24 | Uniden Corporation | Receiver and method for demodulating reception signals |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5377229A (en) * | 1990-12-19 | 1994-12-27 | Motorola, Inc. | Multi-modulation scheme compatible radio |
US6647070B1 (en) * | 1998-09-10 | 2003-11-11 | Texas Instruments Incorporated | Method and apparatus for combating impulse noise in digital communications channels |
KR100339661B1 (en) * | 2000-05-03 | 2002-06-05 | 김춘호 | Apparatus for compensating channel distortion in bluetooth system |
US6487240B1 (en) * | 2000-11-10 | 2002-11-26 | Motorola, Inc. | Apparatus for receiving and recovering frequency shift keyed symbols |
-
2000
- 2000-11-10 US US09/709,687 patent/US6487240B1/en not_active Expired - Lifetime
-
2001
- 2001-02-27 US US09/794,285 patent/US7376207B2/en not_active Expired - Fee Related
- 2001-11-06 JP JP2002543796A patent/JP3968304B2/en not_active Expired - Fee Related
- 2001-11-06 CN CNB018186637A patent/CN100358325C/en not_active Expired - Fee Related
- 2001-11-06 AU AU2002239293A patent/AU2002239293A1/en not_active Abandoned
- 2001-11-06 GB GB0309875A patent/GB2386305B/en not_active Expired - Fee Related
- 2001-11-06 WO PCT/US2001/043413 patent/WO2002041506A2/en active IP Right Grant
- 2001-11-06 KR KR1020037006005A patent/KR100544245B1/en not_active IP Right Cessation
-
2008
- 2008-04-22 US US12/107,603 patent/US7639762B2/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5208835A (en) * | 1990-09-24 | 1993-05-04 | In-Situ, Inc. | Automatic frequency control system and method for frequency-shift-key data transmission systems |
US5852636A (en) * | 1997-08-08 | 1998-12-22 | Serge Mathieu | Method of and apparatus for modulation of FSK carrier in a very narrow band |
US6266521B1 (en) * | 1997-09-02 | 2001-07-24 | Uniden Corporation | Receiver and method for demodulating reception signals |
Non-Patent Citations (2)
Title |
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B. ROHANI AND K.S. CHUNG IEEE 1998, pages 419 - 423, XP002909711 * |
YASUNORI IWANAMI IEEE 1997, pages 310 - 315, XP002909710 * |
Also Published As
Publication number | Publication date |
---|---|
JP3968304B2 (en) | 2007-08-29 |
US20080260072A1 (en) | 2008-10-23 |
WO2002041506A3 (en) | 2002-09-06 |
GB2386305A (en) | 2003-09-10 |
CN100358325C (en) | 2007-12-26 |
US20020057746A1 (en) | 2002-05-16 |
JP2004514368A (en) | 2004-05-13 |
KR100544245B1 (en) | 2006-01-23 |
US6487240B1 (en) | 2002-11-26 |
US7639762B2 (en) | 2009-12-29 |
GB2386305B (en) | 2004-06-30 |
CN1475068A (en) | 2004-02-11 |
US7376207B2 (en) | 2008-05-20 |
KR20030051761A (en) | 2003-06-25 |
AU2002239293A1 (en) | 2002-05-27 |
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